Releasable lock for electric plugs



P 1951 J. J. DALTON RELEASABLE LOCK FOR ELECTRIC PLUGS Filed Dec. 22, 1949 FIG.

INVENTOR JOHN 041. TO

F/G. Q.

ATTORNEYS Patented Sept. 25, 1951 ,QUNITED, STA S PATENT. OFF ICE" I w 2, V J Q RELEASABLE LOOK son- ELEc'rnIo PLUGS f 1 tJoh ninaltomlakewoodfliis i it Q.

Applicationnecember 22, i949, Serial'l flo. 134,380 f' 'I escutcheon plate of duplex electric outlets for releasably securing a single plug, two plugs of equal length, simultaneously, or two plugs of unequal length simultaneously in full contact engagement With the outlet.

-It is an object of this invention .to provide a locking device of the :kind to be more particularly described hereinafter which is inconspicuous, simple in structure, economical in cost and easy of installation, for attachment to the face of an escutcheon plate of a duplex electric outlet and engageable with a plug or plugs engaged in the outletin such a manner as to prevent the inadvertent detachment of the plug or plugs, as by children or. by the exerting of undue strain on the appliance cord, and yet providing for the ready and speedy removal of the plug or plugs when and as desired.

Another object of this invention is to providea device of this kind formed of a minimum number of essential parts of substantially conventional structure or so fashioned to be formed by conventional machine shop equipment and procedure, the parts being inexpensive yet capable of extended hard use without repair or replacement.

A further object of this invention is to provide an electric plug locking means of this kind for positively securing the plug or plugs in the outlet against accidental separation therefrom and against partial separation or short circuits re- 2 Claims. (01. ire-33o) sulting from partial separation of the plug or plugs from the outlet.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification wherein like reference characters designate like parts throughout the several views, and then more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a side elevation of a plug locking device, constructed according to an embodiment of my invention, engaged in a duplex electric outlet, having a cover or escutcheon plate and simultaneously locking two plugs of equal length in contact position in the outlet, the escutcheon plate being shown in longitudinal section;

, Figure '2 is a front elevation;

Figure 3 is a perspective view of the locking post element removed from the assembly of the device;

Figure 4 is a perspective view of the retainin bolt removed from the assembly of the device;

assembly; 1

Figure 5 is a perspective view of the top of one of the locking plates or yokes removed from the -Figure*6 is a' perspective view of the bottom of one of the-locking plates or yokes removed from theassemblyy 1 1 1 Figure 7 a side elevation of the plug locking device as applied when locking two plugs of different lengths; v Ii Figure 8 is a side-elevation showing the locking post in position as protective-shield over the retaining bolt when no plugs are being used in the duplex outlet; V. V v

Figure 9 is a longitudinal section through the locking post removed from the assembly.

Referring to the drawings wherein like reference characters designate likev parts throughout the several views, the numeral [0 designates generally a locking device constructed according to an embodiment of my? invention forreleasably securinganelectrical appliance cord plug to an escutcheon plate [2 overaconventional style and type of duplex electric outlet [4. The locking device lll is adapted to simultaneously lock twin plugs of, the same length, to simultaneously lock two plugs of different lengths, or to look a single plug on escutcheon plates having two outlet openings as generally used in wiringcircuits of homes, .ofiices, commercial buildings, etc.

The locking device I0 is formedwith a central screw member l5 adapted for connection in the central aperture I6 of the escutcheon plate l2 in place of the usualcountersunk screw, not shown in the drawings. The screw member I5 is formed with an integral,- reduced diameter, threaded mounting screw end or portion I! adapted to be slidably' engaged through the -mounting hole or countersunk aperture l6 of the escutcheon plate i2. and threadably engaged with the nut element or member 3 of the outlet base I9 fixedly mounted in the Wall or other supporting structure and on which the sockets 14 are mounted.

v The other portion of the screw member [5 is formed with an integral screw 20 equipped with a screw driver slot and having an outside diameter greater than the outside diameter of the mounting screw end or portion H, for use in a manner to be more particularly described hereinafter. The inner endof base screw 20 is joined to the outer end of the mounting screw. I! by a tapered shoulder 2 I. 1 The tapered shoulder 2| is adapted to be seated in the marginal depression of the aperture IE or countersunk face of the escutcheon plate I! for limiting the threaded engagement of tudinally spaced apart, circular plates or discs- 26 along the length thereof. g ars her or post 22 is adapted tobe engaged on the base screw member 20 between adjacent male A pair of locking yokes 28 5529' are mined for releasable engagement with looking -post' '22-.

and an adjacent electrip cord 21 where cord 21 emerges u w r i mlml icennect r pigs H carried by the z ee ecl re p n. Each of the yokes 28 and 29 is formed of a flat plate @11 nonconducting or insulating material formed i e laterally .c j sc face; 3!. at. .nne. nd. rThe yokes 28 and 29 are distinguishedsfmlmueach oth r only b it ie structure wherein one .Q t plates has a ea 'na d ofiset faces! extending laterally from the front face of theplate ,a: disfiance fi rcnt from :the onset ,.ofi rearwardly offset face of theother yoke memher. By such relative configuration, .the front '"faces of the yokes 28 and 29 may be offset from Zeaoh other on the mounting post 22, as noted. in Figure 1 of the drawings. and :the rearwardly offset faces of the yokes may lie :in 'the same .plane :for engaging .the outer ends .of ,similar ilength plugs I'I engaged :in sockets .1! covered bylescutcheon plate I2. At such (times when .adjac'ent plugs, as plugs .LlAand 1 13, noted in Figure-7 :of the drawings, are engaged zin the socket's'covered by plate I2, and these .plugs'are'ofidifferent lengths and/or configurations, :the yokesmay -be positioned on the post-22 to suit-the particular plug with which it is to be .lockinglyenga'ged.

The yokes, both yoke 28 and yoke '29, are formed with a pair of U-shaped notches 32 and 34 opening-on one side edge. 'O ne'-notoh,' as the notch 32, is positioned transversely of the plate at one end, the fiat end, while the-other slot 34 is inclined at an angle to the longitudinal axis of the plate at the other-oroffs et en d and opens adjacent the transverse median armg plate. The transverse slot-32 of each plate jar yoke is adapted to be slidably' positioned be tween a pair of adjacent disfiplat'es E2on the locking post 22 for 'slidingand-r'otamg engagement on the post at aselected po on. inclined slot 34 is adaptedto rece e the cord 2'! of an electric applianceor the like for seicuring the plugs I l engaged by the pron s thfireof in the socket M against lnadvertent'remoyal from the socket, the onset face of the yokebeing spaced from the escutcheonplate {2 a select:- ed distance very close to the depth Qr length of the plug I I. In the case of the,p1u s bing of different lengths, one orboth yokes'may reversed in their engagfementj between 'the disc plates 26 on the locking,pgstl 22, so thatltheflat side of one, or both yokes,' 'is s pacedrr ornf'the III escutcheon plate l2 a selected distance verygclojse to the depth or length of the plug, this multiplicity of arrangements of the yokes between the disc plates 26 permits of a wide range of spacings between the yoke face and the escutcheon plate.

With a plug ll engaged between a yoke 28 or 29 and the escutcheon plate 12, the yoke or yokes may be securely clamped to the plug H by rotating the locking post 22 inwardly along the plug H from the socket 14, it is necessary only to rotate post element 22 outwardly along the length of base screw 20 and slide the yoke transversely, of, the mounting post, as noted by the broken lines'in Figure 2 of the drawings.

lE -do" not mean to confine myself to the exact details I of construction herein disclosed, but maimed variations 'falling within the purview of the appended claims.

I claim: I

,1. A releasable c g d v c or. cmov securing an electric plu to a rel e cket comprisinga locking post, a plurality of spaced apart coaxial discs on-said post, means securing said post on an escutcheon plate in adjusted spaced relation therefromya pair of locking plates slidably and rotatablyen ageable 011 said p.0 1". 63.011 of said locking plates having a laterally openingnotch for slidablyengagin Said post between a pair of adjacent discs, at least one of said locking plates'having .an offset end for .disposition in the same transverse plane as the other locking plate when engaged between an.- other pair .of discs .on said post, the outerflends of each of said'locking plates having an opensided notch for slidably receivin an electric cord having a plug thereon for clampingly vse-- curing the plug between the respective locking plates and-theescutcheon plate.

2. A releasable locking device for removably securing an electric plug including a cord'to an outlet socket inan electric wall fixture comprising a-locking post adapted to be arranged transversely of said fixture and having'one end adapted to be fixedly secured to said fixtureadjac'ent said socket, a plurality of spaced apart discs fixedly positioned along said post' inwardly of'the other end thereof, a locking plate positioned transversely of said post and having a notchextending inwardly of one side edge adjacent one end thereof islidably and rotatably embracing any selected portion of saidpost intermediate adjacent discs, and means embodying a second notch formed in said locking plate and extend ing inwardly of one side edge of said' plate jadjacent'the other end for embracingly engaging the portionof the cord adjacent the electridplug andbearing' against the adjacent end of said plug whenthe latter is inserted in said socket."

JOHN J. DALTON.

REFERENCES CITED (Ifhe following references are of record in .the file I thi Pat n OBrie'n Dec. 12, 1944, 

